Aart- Final Report on-PRE

Online Internship Programme (OIP2021) Internship Report On

Petroleum Refinery Engineering (PRE) Submitted in Partial Fulfilment of the Requirements for the mandatory Internship training programme

Submitted by: Aarti Angadrao Ambhure



19rd June to 25st July, 2021

Indian Institute of Chemical Engineers (IIChE) Dr. H. L. Roy Building, Jadavpur University Campus,

OIP-2021 188 Raja Subodh Chandra Mullick Road, Kolkata 700 032 www.iiche.org.in / [email protected]

Certificate from the IIChE

This is to certify that

Mr./Ms……… Aarti Angadrao Ambhure

From…Department Of Chemical Engineering Institute Of MGM’S JNEC Aurangabad Maharashtra… .has successfully completed online internship programme in our organization. The matter embodied in this report is a genuine to the best of our knowledge and belief and has not been submitted before, neither to this Institute nor to any other organization for the fulfilment of the requirement of any course of study. During his internship tenure in IIChE, we found him/her hard working, sincere, and diligent person and his behaviour and conduct was good. We wish him all the best for his future endeavour.

Chief Coordinator, OIP-2020

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OIP-2021 Acknowledgement

The internship opportunity I had with IICHE was a great chance for learning and professional development. Therefore, I consider myself as a very lucky individual as I was provided with an opportunity to be a part of it. I am also grateful for having a chance to meet so many wonderful people and professionals who led me though this internship period. Bearing in mind previous I am using this opportunity to express my deepest gratitude and special thanks to chief coordinator who in spite of being extraordinarily busy with his duties, took time out to hear, guide and keep me on the correct path. I express my sincere gratitude to Prof. Dr. Avijit Ghosh (IIChE) and Prof. Subhojit sarkar(IOCL) for granting me this opportunity where I got to know,learn and develop deep understanding about the Refinery Industrial Processes and Petrochemicals Industries as well, I also extend my sincere thanks to Mr. Kisalay Kumar (Course Coordinator) for constantly guiding, supporting and proving the necessary Resources to me for completing my project/training I perceive as this opportunity as a big milestone in my career development. I will strive to use gained skills knowledge in the best possible way, and I will continue to work on their improvement, in order to attain desired career objectives. Hope to continue cooperation with all of you in the future.

Sincerely Aarti [email protected]

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Objectives of Online Internship Program •

Assist the student's development of employer-valued skills such as teamwork, communications and attention to learn Engineer’s responsibilities and ethics.

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Enhance and/or expand the student's knowledge of a particular area(s) of skill.

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Expose the student to professional role models or mentors who will provide the student with support in the early stages of the internship and provide an example of the behaviours expected in the intern's workplace.

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To familiarize with various materials, processes, products and their applications along with relevant aspects of technology and troubleshooting.

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To gain experience in writing technical report/project.

Course Outcome •

The basic idea of different real life industrial problems, trouble shooting, decision making and preventive maintenance techniques and professional culture of industry, work ethics and attitudes in industry. The different live situation, trouble shooting and modern technological application.

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Course materials to be provided to the students for reference (in PDF format). The study material will be shared with the students through IIChE for its record.

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Assignment will be given for the solution / conceptual idea and which may be discussed during the tutorial class.

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Mini project will be given for developing their analytical ability which helps them to realize the value of practical training.

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Importance will be given on the application of modern tools for the industrialautomation / up-gradation / scale-up.

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Conceptual theory for the regular class room discussion and its application is real-life industrial problem resolution.

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Case studies based on real life application.

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Content 1. Introduction

2. Discussion on different industrial Processes & applications

3. Case study analysis (if any)

4. Scope of Research and development activity

5. Summary

6. My observation / Openion

7. Appendix: All assignments

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1. Introduction: Overview of the Industry In oil refineries we refine crude and make many products like Petrol, High speed diesel, Kerosene, ATF, Light Naphtha. High Naphtha. LPG. Refineries produce many profitable products however, the high-volume profitable products are the transportation fuel gasoline. Diesel and turbine (jet) fuels, and the light heating oils. Although products such as lubricating oils, refrigeration and transformer oils, and petrochemical feedstocks are profitable. They amount to less than 5 percent of the total crude oil charged to refineries. Refineries are very large industrial complexes that involve many different processing units and auxiliary facilities such as utility units and storage tanks. Each refinery has its own unique arrangement and combination of refining processes largely determined by the refinery location, desired products and economic considerations. Indian Chemical Engineer (ICE) is a journal of Indian Institute of Chemical Engineers which has been the Institute’s main organ since 1959. Even before ICE, IIChE regularly published Transactions of Chemical Engineers between 1948 and 1958. Prof. G.S. Laddha was the first Editor of ICE. A renowned Chemical Engineer, Prof. Ladhha has been known for his research on liquid–liquid extraction. He is also recognised for his contribution to the establishment of several chemical industries in India. Since, Prof. Laddha, there have been 15 other Editors, all consummate academics, under whose aegis the journal has been published till date.The journal’s Editorial Board and the International Advisory Board also include eminent Professors and Scientists from India and abroad. ICE offers an international platform for publishing articles on original research initiatives, interpretative reviews and overviews on new developments in the realm of Chemical Engineering and allied fields. Special Issues of ICE, published periodically, are rich sources of information with contributions from noted academics and research scholars, in the upcoming areas.

Since 2011, ICE is published by Taylor and Francis, UK, one of the world’s leading publishers of scholarly journals and books. Collaboration with Taylor & Francis has facilitated a wide international readership for the journal along with high-quality logistic support and has added a professional finesse to the journal. Authors can submit their papers Indian Institute of Chemical Engineers

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OIP-2021 online using ScholarOneManuscriptsTM (https://mc.manuscriptcentral.com/tice), which would undergo a thorough peer review process before being selected for publication.

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OIP-2021 2. Discussion on different industrial application In a Refinery Industry there are numerous Process units together which combine to form Process configuration which perform different operations and these operations are called Industrial Processes. Some of the basic Refinery Industry Processes are as follow: 1. Separation processes a) Atmospheric distillation b) Vacuum distillation e) Light ends recovery (gas processing) 2. Petroleum conversion processes a) Cracking (thermal and catalytic) b) Reforming c) Alkylation d) Polymerization e) Isomerization f) Coking g. Visbreaking 3. Petroleum treating processes a) Hydrodesulfurization b) Hydrotreating c) Chemical sweetening d) Acid gas removal e) Deasphalting 4. Feedstock and product handling a) Storage b) Blending c) Loading d) Unloading This is the Refinery Scheme which includes various Indutrial Processes:

CRUDE PRETREATMENT: Desalting A Desalter is a process unit in an oil refinery that removes salt from the crude oil. The salt is dissolved in the water in the crude oil, not in the crude oil itself. The desalting is usually the Indian Institute of Chemical Engineers

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OIP-2021 first process in crude oil refining. The salt content after the desalter is usually measured in PTB-pounds of salt per thousand barrels of crude oil. Another specification is Basi sediment and water. Theory of desalting Crude oil contains many undesirable impurities. These impurities can present many varied problems during the refining process. The purpose of desalting is to remove these undesirable impurities from the crude oil stream prior to distillation.

The most common inorganic salts present in the crude oil are: •

Sodium Chloride, (NaCl)

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Magnesium Chloride, (MgC12)

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Calcium Chloride, (CaC12)

Salt content in a crude depends mainly on source of the crude.

The most common concern is inorganic salt decomposition in the crude oil pre-heat exchangers and heaters. As the salts decompose, hydrogen chloride gas is formed, which condenses to form liquid hydrochloric acid at the initial condensation point of water. This initial point of water condensation usually occurs in the crude overhead system, though it can occur in the tower itself, if operational conditions allow it.

OPERATING VARIABLES: TEMPERATURE: 130 DEG. C PRESSURE: 8-11 kg/cm2 Outlet crude salt content: <0.5 ptb Brine oil content: 165 ppm (max) WATER INJECTION RATE: 4-6% Vol. Of Crude INTERFACE LEVEL: 40-50% DEMULSIFIER INJECTION: 6-8 ppm on crude Benefits Resulting From Desalting 1.Increased crude throughput by:: ● Longer runs • Running at maximum capacity. ●Less down time for maintenance – Indian Institute of Chemical Engineers

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OIP-2021 • Uniform crude charge without slugs of water during tank switching 2.Less plugging, scaling, coking and slagging of: ● Exchangers Furnaces 3.Relief from catalyst poisoning by: •

Arsenic in platformers

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Sodium, iron and other metals in crackers, delayed coker ATMOSPHERIC DISTILLATION :

In the refining process, the atmospheric distillation unit (ADU) separates the lighter hydrocarbons from the heavier oils based on boiling point. The ADU is capable of boiling crude oil fractions to temperatures of 750°F. Above this temperature, the oil will thermally crack, or break apart, which impedes the distillation process. As lighter products are boiled off, the heavier oils, called bottoms, remain at the bottom of the ADU. To increase the production of high-value petroleum products, these bottoms are run through a vacuum distillation column to further refine them.

VACCUM DISTILLATION: Vacuum distillation is a part of the refining process that helps to produce petroleum products out of the heavier oils left over from atmospheric distillation. As the name vacuum distillation implies, the distillation column is under a vacuum, or significantly less than atmospheric pressure of 760 millimeters of mercury (mmHg). At low pressures, the boiling point of the ADU bottoms is low enough that lighter products can vaporize without cracking, or degrading, the oil. Vacuum distillation produces several types of gas oil. These are slightly heavier than middle distillates such as jet fuel, kerosene, and diesel. In the next stage of refining, these gas oils are further refined to make products such as light-cycle oil (a type of distillate), gasoline, and naphtha. This is the beginning of the refining process. Distilling exploits the characteristic of the chemicals in crude oil to boil at different temperatures, a phenomenon that engineers chart along distillation curves. Unlike a still, a distilling column contains a set of trays that allow

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OIP-2021 heated vapors to rise and collect at different levels, separating out the various liquids derived from crude oil. The top of the column is cooler than the bottom, so as liquids

Vaporize and rise, they condense again, collecting onto their respective trays. Butane and other light products rise to the top of the column, while straight-run gasoline, naphtha. Kerosene, diesel, and heavy gas oil gather on the trays, leaving straight run residue at the base of the column. CONVERSION PROCESSES: Fluidized catalytic cracking(FCC) FCC is catalytic cracking process. Cracking is a process for conversion of bigger Hydrocarbon molecules to smaller hydrocarbon molecules by raising temperature and Pressure. Catalytic cracking gives more stable products. The unit is one of the most important units of the modern refinery. The unit enables the successful transformation of desulfurized HVGO to lighter products such as unsaturated light ends, light cracked naphtha, heavy cracked naphtha, cycle oil and slurry. Thereby; the unit is useful to generate lighter products from a heavier lower value intermediate product stream. Conceptually, the unit can be regarded as a combination of chemical and physical processes. The process flow of the entire unit can be divided in to 3 sections. pre-heat section: Surge drum, feed pump, feed preheat exchangers and feed furnace. Catalyst section: Riser, Reactor cyclone, Reactor stripper. Regenerator, Regenerator cyclone, Orifice chamber. Main air blower, catalyst storage system. Fractionation section: Fractionator column, side cut strippers (HN & LCO), Circulating system /P.A (HN, LCO.HCO and Bottom), Overhead surge drum, Bottom circulation system & draw system. FCC Catalyst Fine Porous Powder (APS: 70-75 u) Acts like fluid when aerated (fluidised) Oxides of Silica & Alumina FCC products •

Dry gas (H2, C1, C2)

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LPG (C3, C4) Propylene, Iso-butylene

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Gasoline (C5-150C)

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Heavy cracked naphtha (LCN) (150-220C)

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Light cycle oil (LCO) (220-370C)

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Clarified oil (CLO) or Decant oil (DO) Hydro cracking unit:

It is a key catalytic conversion process to transform heavy, high boiling, low value and wide variety of feed stocks to premium quality lower boiling high value products by carbon carbon Indian Institute of Chemical Engineers

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OIP-2021 bond scission accompanied with simultaneous or sequential hydrogenation at high hydrogen pressure and high temperature. BENEFITS OF HYDROCRACKING • Middle Distillate yield is 80% as compared to 45% in FCCU • Entire feed stock can be converted to the product range i.e. no coke or by products Low Sulphur, Nitrogen and Aromatic content in Products

Application and Product Specification: The Hydrocracking process in a Refinery is used to give fuel like Diesel, Naphtha, etc. The Hydrotreating process is used to remove impurities from Diesel feed. The module covers an Integrated HCU unit and DHT unit that utilizes a common Make-up gas compressor, Recycle gas compressor and Light Ends recovery system.

DELAYED-COKING: A delayed coker is a type of coker whose process consists of heating a residual oil feed to its thermal cracking temperature in a furnace with multiple parallel passes. This cracks the heavy, long chain hydrocarbon molecules of the residual oil into coker gas oil and petroleum coke. The yield of coke from the delayed coking process ranges from about 18 to 30 percent by weight of the feedstock residual oil, depending on the composition of the feedstock and the operating variables

The delayed coking operating variables include heater outlet temperature, pressure, recycle ratio, and cycle time. These variables are selected based on feed properties such as the characterization factor, asphaltene content, and Conradson Carbon Residue (CCR) to ensure Indian Institute of Chemical Engineers

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OIP-2021 that coking in tubular heaters is minimized and liquid product yield is maximized. The recycle ratio, which is typically 3-5%, is used to control the endpoint of the coker heavy gas oil. The coke yield can vary from 20% to 30% depending on the feed properties and coking conditions.

Visbreaker A visbreaker is a processing unit in an oil refinery whose purpose is to reduce the quantity of residual oil produced in the distillation of crude oil and to increase the yield of more valuable middle distillates (heating oil and diesel) by the refinery. A visbreaker thermally cracks large hydrocarbon molecules in the oil by heating in a furnace to reduce its viscosity and to produce small quantities of light hydrocarbons (LPG and gasoline). The objectives of visbreaking are: • Reduce the viscosity of the feed stream: • Reduce the amount of residual fuel oil produced by a refinery: • Increase the proportion of middle distillates in the refinery output: Feed quality and product quality Application and Product Specification: A visbreaker is a processing unit in an oil refinery whose purpose is to reduce the quantity of residual oil produced in the distillation of crude oil and to increase the yield of more valuable middle distillates (heating oil and diesel) by the refinery. A visbreaker thermally cracks large. hydrocarbon molecules in the oil by heating in a furnace to reduce its viscosity and to produce small quantities of light hydrocarbons (LPG and gasoline). The process name of "visbreaker" refers to the fact that the process reduces (i.c.. breaks) the viscosity of the residual oil. The yields of the various hydrocarbon products will depend on the "severity" of the cracking operation as determined by the temperature the oil is heated to in the visbreaker furnace. At the low end of the scale, a furnace heating to 425 °C would crack only mildly. while operations at 500 °C would be considered as very severe.

TREATMENT:

DHDS/DHDT: The objective of the Diesel Hydrotreater (DHDT) Unit is to produce a low-sulfur product along with cetane improvement. ● The design capacity is 2.86 MMTPA ●The unit is designed for a stream factor of 8,000 hours per year and a turndown ratio of 50% of the unit design capacity. Indian Institute of Chemical Engineers

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OIP-2021 There are two primary products from the DHDT unit. Stabilized Diesel Stabilized Naphtha Process comprises of 5 main sections: Feed section Feed filter Preheat exchangers (Breach lock exchangers) Furnace . Reactor circuit section ( Two reactors in series) Separation & Compression section. H.P. and M.P. Separators Recycle gas and Make up gas Compression .L.P. Section comprising of Stripper, Stabilizer and Product Section. . Amine Section (H.P..M.P. & L.P. amine absorbers) Operating DHDT: . Critical handling of of H2S/H2 • High pressure operation of HP Section. Purity of product • Feed quality Amine column operation . MUG Compressor operation • Breech lock exchangers operation Application and Product Specification: DHDS/DHDT is a catalytic chemical process widely used to remove sulfur (S) from natural gas and from refined petroleum products, such as gasoline or petrol, jet fuel, kerosene, diesel fuel, and fuel oils. The purpose of removing the sulfur, and creating products such as ultra lowsulfur diesel, is to reduce the sulfur dioxide (SO2) emissions that result from using those fuels in automotive vehicles, aircraft, railroad locomotives, ships, gas or oil burning power plants, residential and industrial furnaces, and other forms of fuel combustion.

CATALYTIC REFORMING Objective To convert low Research Octane number (RON) Naphtha to high RON reformate (MS/Gasoline blending component) • Position of CRU in Refinery Configuration: ➤ CRU is the primary unit for production of Motor Spirit/Gasoline/Petrol from a Refinery ➤ Indian Institute of Chemical Engineers

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OIP-2021 CRU unit is designed to treat Straight Run Naphtha (SRN) ex Atmospheric unit (mother unit) Normal cut range of SRN varies between C5 boiling point to 150 “C (FBP) (RON of-60) > This SRN is split into two components namely light Naphtha (C5-90 °C) and Heavy Naphtha (90-150 °C) Fixed bed • Semi-regeneratie (SR) • Cyclic Reformer Continuous regeneration (CCR) CRU Types: Following are the types of CRU units based on design: • Fixed bed • Semi-regeneratie (SR) • Cyclic Reformer Continuous regeneration (CCR) Application and Product Specification Catalytic reforming is a chemical process used to convert petroleum refinery naphthas distilled from crude oil (typically having low octane ratings) into high-octane liquid products called reformates, which are premium blending stocks for high-octane gasoline. The process converts low-octane linear hydrocarbons (paraffin’s) into branched alkanes (isoparaffins) and cyclic naphthenes, which are then partially dehydrogenated to produce high-octane aromatic hydrocarbons.

Blending

The last major step of the refining process is blending various streams into finished petroleum products. The various grades of motor fuels are blends of different streams or “fractions” such as reformate, alkylate, catalytically cracked gasoline, etc. Refineries blend compounds obtained either from their internal refining process operations as noted above, or externally. To make gasoline that meets specifications for acceptable motor vehicle performance. A typical refinery may produce as many as 8 to 15 different streams of hydrocarbons that they must mix into mo r fuels. Refiners might also mix in additives like octane enhancers, metal deactivators, anti-oxidants, anti-knock agents, rust inhibitors, or detergents into their hydrocarbon streams. Blending can take place at the refinery along the pipelines and tanks that house processed fuel or even at off-site locations or on ships or terminals once the fuel has left the refinery gate.

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3. Case study analysis The COVID-19 Pandemic had introduced a lot of changes in the conventionally followed lifestyle. The IIChE Kolkata Summer Internship was one of these changes. Owing to the difficulty for the Student to do an on-site summer internship during the pandemic times, the All India Council for Technical Education (AICTE) advised students to opt for an online summer training as an Alternative option. In view of this, IIChE Kolkata decided to provide an online summer training For students on various topics related to the chemical engineering curriculum such as Process Safety Management (PSM), Petroleum Refinery Engineering, Petrochemical Engineering, Chemical Process Technology, Zero Liquid Discharge Management (ZLD), Six-Sigma Training, And Biochemical Process Plant. It was a paid online internship for duration of 4 weeks. The online Training was provided by eminent experts from the different esteemed industry along with the Organizational members of the IIChE. A panel was formed for this internship that spanned over People take around 55 industries and 42 institutes. The eminent experts engaged with the students to provide online summer training. The mode of online training comprised of various activities Such as webinar discussion, assignments, problem-solving, report writing, and finally, the students Were graded in accordance with these parameters. Further, it was split into 3 batches in order to Accommodate a good deal of students.

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4. Research and development A number of technology areas have been identified as high priority needs for the petroleum industry.It is important to note that certain principles should guide the development of industry-wise collaborative research efforts. These principles are summerized below: Potential users should identified if research is needed. Research should develop new, precompetitive technology. Research should provide a mechanism to ower the cost of compliance with Environmental regulations. All research should benefit the public and industry as well. There are also some technology areas in which individual petroleum companies have active Research. There may also be pre-competetive projects these technologies that meet the principles for collaborative research and may alsobenefit society. One source of emission at refineries is from petrochemical process heaters. From time to time central regulatory bodies conduct test on emissions to measure its toxicity level and further Toxic Combustion By-products Research would be useful. Testing for polychlorinated dibenzodioxins, dibenzofurns and Biphenyls is one possibility. Sensor Technology DOE’s national laboratories have shown substantial expertise and research capability in Sensor technology. Chemical sensors that can detect small concentratins of hydrocarbons in Gas streams and physical sensors that measure temperature and pressure could be studied to Determine their possible use in a processing environment. Vehicle Emission Measurements of emission from vehicles has been an excellent area for cooperative research. As emission standards and advanced technology vehicles are introduced, additional tests will be required. Pressure will continue for changes to be made in both gasoline and diesel fuel composition. Introduction of Bharat Stage-VI(BS-VI) standards in fuels is an excellent example which has drastically cut down the emission levels by vehicles. Hence, there is an Indian Institute of Chemical Engineers

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OIP-2021 opportunity of research and development to meet the required standards efficiently and effectively. Reprocessing Petroleum Waste Continual improvement is neede to reprocess efficiently and safely petroleum waste streams such as heat exchanger cleaning residue. Current synthetic dril fluids adhere to offshore discharge cuttings, necessitating expensive disposal approaches. Research could lead to reduced levels of synthetics on cutting, which would reduce the environmental impact of offshore drilling. Making Carbon Dioxide an Asset Reliance considers carbon dioxide an asset, not a liability. In pursuit of a sustainable and low emission future, Reliance has developed a technology called Energy Integrated Circulating Fluidized Bed Process for CO₂ Capture. This is an adsorption-based process that follows carbonate-bicarbonate chemistry. The in-house energy integrated capture process has the following excellent attributes: improved adsorbent system with good mechanical strength and high adsorption capacity circulating fluidized bed reactor system - lower temperature differential between adsorption -desorption step -recovery and utilization of flue gas heat to compensate partial heat demand - heat pump concept for upgradation of low quality waste heat for adsorbent regeneration less than one half total energy as compared to conventional monoethanolamine absorption process etc. Catalysts in petroleum refining and petrochemical industries Catalysis plays an increasingly critical role in modern petroleum refining and basic petrochemical industries. The market demands for and specifications of petroleum and petrochemical products are continuously changing. They have impacted the industry significantly over the past twenty years. Numerous new refining processes have been developed and significant improvements were made on existing technologies. Catalytic reforming process is used in refining for production of aromatics such as, benzene, toluene and xylene. Reliance has adopted a novel approach to developing reforming catalyst for Continuous Catalytic Regeneration (CCR) process. The catalyst is prepared by coating a promoter on spherical shaped chloride-free alumina as support. This catalyst- which is first of Indian Institute of Chemical Engineers

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OIP-2021 its kind in the world is an optimized high-performance catalyst that enhances stability and increases C5+ and aromatic yields. Alloy selection System for Elevated Temperatures It is necessary to improve data collection concerning corrosion of metals and alloys by high temperatures gases. Reseach should lead to the development of a computer program to predict the corrosion rate for different materials based on a fumdamental understanding of atomic and molecular structures. Desulfurization Research on novel methods of sulphur removal from crude oil and petroleum based transportation fuels could provide a more cost-effective method of desulfurization than conventional methods. Energy EEfficiency Methods to improve energy efficiency are always needed. Future invironmental concerns on global climate change could change any foster regulations that limit CO2 emissions, making some new technologies economically feasible. The petroleum industry needs to find ways to reduce fouling in heat exchangers. Novel Methods to reduce Greenhouse Gases The effect of greenhouse gases on global warming is a subject of worldwide debate. Nevertheless, there could be corollaries such as improved energy efficiency from discovering novel methods to reduce greenhouse gases such as CO2.Methods for reducing recovering. And/or re-using these gases should be explored to reduce their impact on environment. Additional Research Areas:The following are the list of technologies includes areas where Petroleum companies need R&D projects: •

Novel catalyst and process development

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Improving computational technologies

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Cogeneration

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5.

Summary

Petroleum refinery is a technology that uses fossil fuel as a raw material. Chemical catalysts a means to achieve conversion of petroleum through once twice a deep processing to get a series of chemical products which are further used as the basic raw material for plastic, synthetic rubber, chemical fertilizers & pesticides in production. Hence, petroleum refining plays an important role in people live. Crude oil is heated in a furnace and charged to an atmospheric distillation tower, where it is separated into light gas (C1-C4), light naphtha, heavy naphtha, kerosine, atmospheric gas oil, and reduced (topped) crude. The reduced crude is sent to the vacuum distillation tower and separated into vacuum gas oil stream and vacuum reduced crude bottoms (residua, resid). The reduced crude bottoms from the vacuum distillation tower is thermally cracked in a delayed coker to produce gas, coker gasoline, coker gas oil, and coke. The atmospheric and vacuum crude unit gas oils and coker gas oil are used as feedstocks for the catalytic cracking or hydrocracking g units where heavy molecules get converted into lower molecular weight compounds boiling in the gasoline and distillate fuel ranges. The hydrocracked products are saturated whereas catalytic cracker products are unsaturated and further need improvement in by either quality by r hydrotreating or by reforming. The light naphtha streams from the crude tower, coker and cracking units are sent to an isomerization unit to convert straight-chain paraffins into isomers which have higher octane numbers. The heavy naphtha streams from the crude tower, coker, and cracking units are fed to the catalytic reformer improve octane numbers. The products from the catalytic reformer can be blended into regular and premium gasolines for marketing. The wet gas streams from the crude unit, coker, and cracking units are separated in the vapor recovery section (gas plant) into fuel gas, liquefied petroleum gas (LPG), unsaturated hydrocarbons (propylene, butylenes, and pentenes), normal butane, and isobutane. The fuel gas is bumed as a fuel in refinery furnaces and the normal butane is blended into gasoline or LPG, The unsaturated hydrocarbons and isobutane are sent to the alkylation unit 1 o react olefins with isobutane to yield isoparaffins. The alkylation is done at high pressure and low. Low temperature I in the presence of sulfuric or hydrofluoric acid as catalyst. The product is called alkylated gasoline, which is a high-octane product blended into premium motor gasoline and aviation gasoline. The middle distillates from the crude unit, coker, and cracking units are blended into diesel and jet fuels and furnace oils. In s some refineries, the eries, heavy vacuum gas oil and reduced crude from paraffinic or naphthenic base crude oils are processed into lubricating oils. The asphaltenes are removed in a propane deasphalting unit, and the reduced crude from bottoms are processed with the vacuum gas oils to produce base (LOBS). The vacuum gas oils and deasphalted stocks are solvent-extracted to remove the aromatic Indian Institute of Chemical Engineers

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OIP-2021 compounds followed by dewaxing to improve the pour point. These LOBS are further treated with acid clays to improve their color and stability before being blended into lubricating oils. Each refinery has its own unique processing scheme which is determined by the process equipment available, crude oil characteristics, operating costs, and product. Along with the Petroleum Refinery the OSIP also covered Petrochemicals section which includes all the valuable and marketable products produced from a refinery along with the fuels. There are numerous applications of these products. Petrochemicals refer to the chemical products derived from the petroleum industries. The various polymerization products like polypropylene, ribber, plastics, wax and many more are an important synthetic producs produced from a petroleum refinery. The physical and chemical properties of the products along with their applications are also discussed. The categories of First, Second and Third Generation Petrochemicals are covered this OSIP. Various Polymerization techniques along with their advantages and disadvantages are discussed. Trouble-shooting techniques of the naphtha cracking unit and other process units are also covered in this OSIP along with the Process Safety Management which is necessary for any industry that utilizes hazardous chemicals onsite, has a risk of explosion, fire.

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6.

Appendix: All the assignment

Name:- Aarti Angadrao Ambhure E-mail ID:- [email protected]

Assignment-1: Kindly Explain the major Elements in details Which we have to Consider to establish a New refinery in a Particular area of a Country including Safety & Quality Aspects also. Ans:-

Petroleum refining is mainly aimed at transforming crude oil into useful goods such as LPG, gasoline, jet fuel, diesel oil, jet fuel and fuel oils.

Processing configurations Each petroleum refinery is uniquely configured to process a specific raw material into a desired slate of products. In order to determine which configuration is most economical, engineers and planners survey the local market for petroleum products and assess the available raw materials. Since about half the product of fractional distillation is residual fuel oil, the local market for it is of utmost interest.

Topping and hydroskimming refineries The simplest refinery configuration, called a topping refinery, is designed to prepare feedstock’s for petrochemical manufacture or for

production of industrial fuels in remote oil-production areas. It consists of tankage, a distillation unit, recovery facilities for gases and light hydrocarbons, and the necessary utility systems (steam, power, and water-treatment plants). Topping refineries produce large quantities of unfinished oils and are highly dependent on local markets, but the addition of hydro treating and reforming units to this basic configuration results in a more flexible hydroskimming refinery, which can also produce desulfurized distillate fuels and high-octane gasoline. Still, these refineries may produce up to half of their output as residual fuel oil, and they face increasing economic hardship as the demand for high-sulfur fuel oils declines.

Unit operations in a hydroskimming refinery. Nonshaded portions show the basic distillation and recovery units that make up a simple topping refinery, which produces petrochemical feedstock and industrial fuels. Shaded portions indicate the units added to make up a hydro skimming facility, which can produce most transportation fuels.

Conversion refineries The most versatile refinery configuration is known as the conversion refinery. A conversion refinery incorporates all the basic building blocks

found in both the topping and hydroskimming refineries, but it also features gas oil conversion plants such as catalytic cracking and hydrocracking units, olefin conversion plants such as alkylation or polymerization units, and, frequently, coking units for sharply reducing or eliminating the production of residual fuels. Modern conversion refineries may produce two-thirds of their output as gasoline, with the balance distributed between high-quality jet fuel, liquefied petroleum gas (LPG), diesel fuel, and a small quantity of petroleum coke. Many such refineries also incorporate solvent extraction processes for manufacturing lubricants and petrochemical units with which to recover high-purity propylene, benzene, toluene, and xylenes for further processing into polymers.

Unit operations in a conversion refinery. Shaded portions indicate units added to a hydroskimming refinery in order to build up a facility that can convert heavier distillates into lighter fuels and coke.

Off-sites The individual processing units described above are part of the processunit side of a refinery complex. They are usually considered the

most important features, but the functioning of the off-site facilities are often as critical as the process units themselves. Off-sites consist of tankage, flare systems, utilities, and environmental treatment units.

Tankage Refineries typically provide storage for raw materials and products that equal about 50 days of refinery throughput. Sufficient crude oil tankage must be available to allow for continuous refinery operation while still allowing for irregular arrival of crude shipments by pipeline or oceangoing tankers. The scheduling of tanker movements is particularly important for large refineries processing Middle Eastern crudes, which are commonly shipped in very large crude carriers (VLCCs) with capacities of 200,000 to 320,000 tons, or approximately two million barrels. Nonvolatile products such as diesel fuel and fuel oils are stored in largediameter cylindrical tanks with low-pitched conical roofs. Tanks with floating roofs reduce the evaporative losses in storage of gasolines and other volatile products, including crude oils. The roof, which resembles a pontoon, floats on the surface of the liquid within the tank, thus moving up and down with the liquid level and eliminating the air space that could contain petroleum vapour. For LPG and butanes, pressure vessels (usually spherical) are used.

Flares One of the prominent features of every oil refinery and petrochemical plant is a tall stack with a small flame burning at the top. This stack, called a flare, is an essential part of the plant safety system. In the event of equipment failure or plant shutdown, it is necessary to purge the volatile hydrocarbons from operating equipment so that it can be

serviced. Since these volatile hydrocarbons form very explosive mixtures if they are mixed with air, as a safety precaution they are delivered by closed piping systems to the flare site, where they may be burned in a controlled manner. Under normal conditions only a pilot light is visible on the flare stack, and steam is often added to the flare to mask even that flame. However, during emergency conditions the flare system disposes of large quantities of volatile gases and illuminates the sky.

Utilities A typical refinery requires enough utilities to support a small city. All refineries produce steam for use in process units. This requires watertreatment systems, boilers, and extensive piping networks. Many refineries also produce electricity for lighting, electric motor-driven pumps, and compressors and instrumentation systems. In addition, clean, dry air must be provided for many process units, and large quantities of cooling water are required for condensation of hydrocarbon vapours.

Environmental treatment The large quantity of water required to support refinery operations must be treated to remove traces of hydrocarbons and noxious chemicals before it can be disposed of into waterways or underground disposal wells. In addition, each of the process units that vent hydrocarbons, flue gases, or particulate solids must be carefully monitored to ensure compliance with environmental standards. Finally, appropriate procedures must be employed to dispose of spent catalysts from refinery processing units.

Bulk transportation Large oceangoing tankers have sharply reduced the cost of transporting crude oil, making it practical to locate refineries near major market areas rather than adjacent to oil fields. To receive these large carriers, Deepwater ports have been constructed in such cities as Rotterdam (Netherlands), Singapore, and Houston (Texas). Major refining centres are connected to these ports by pipelines. Countries having navigable rivers or canals afford many opportunities for using barges, a very inexpensive method of transportation. The most efficient mode of bulk transport for petroleum is the network of pipelines that are now found all over the world. Most crudeoilproducing areas are connected by pipeline either to refining centres or to a maritime loading port. In addition, many major crude-oilreceiving ports have extensive pipeline distribution networks to inland refineries. Centrifugal pumps usually provide the pumping power, with booster stations installed along the line as necessary. Most of the major product lines have been converted to fully automated operation, with the opening and closing of valves carried out by automatic sequence controls initiated from remote control centres.

Safety And QualityThe refining process releases a number of different chemicals into the atmosphere (see Compilation of Air Pollutant Emission Factors) and a notable odor normally accompanies the presence of a refinery. Aside from air pollution impacts there are also wastewater concerns, risks of industrial accidents such as fire and explosion, and noise health effects due to industrial noise.

Many governments worldwide have mandated restrictions on contaminants that refineries release, and most refineries have installed the equipment needed to comply with the requirements of the pertinent environmental protection regulatory agencies.

Assignment – 2 Explain In Details, What Is Importance’s Of FCC/RFCCU & Hydro Cracker Units In A Refinery In Bs-vi Scenario And Why AVUs Known As Mother Unit Of Any Refinery? Ans:- FCC Fluid catalytic cracking (FCC) is one of the most important conversion processes used in petroleum refineries. It is widely used to convert the

high-boiling point, high-molecular weight hydrocarbon fractions of petroleum crude oils into more valuable gasoline, olefinic gases, and other products. Cracking of petroleum hydrocarbons was originally done by thermal cracking, which has been almost completely replaced by catalytic cracking because it produces more gasoline with a higher octane rating. It also produces byproduct gases that have more carboncarbon double bonds (i.e. more olefins), and hence more economic value, than those produced by thermal cracking. Fluid catalytic cracking (FCC) is a process technology for converting heavy oils into more valuable gasoline and lighter products with a powdered catalyst.

A number of kinds of advanced process technologies are required in the design and construction of (residue) fluid catalytic cracking FCC equipment. In the reactor, the feed oil is injected and contacted with the catalyst in a fluidized state to convert into C3-C4 olefin and gasoline fraction. The cracked oils are is serially separated into products in the downstream distillation towers. The propylene splitter unit for producing propylene and the cracked gasoline desulfurization unit are also installed in some cases.

The catalyst used in the reaction is circulated back to the reactor after burning off the coke remained on the catalyst particle in the regenerator by air to maintain its activity. The high-temperature energy from the regenerator flue gas is recovered by a flue gas expander as the form of mechanical energy and by the steam generator as the form of heat.

Hydrocracker In a refinery, the hydrocracker upgrades VGO through cracking while injecting hydrogen. This yields a high volume of high-quality diesel and kerosene product. This is in contrast to the FCC, which uses the same feed (VGO) but produces more and better-quality gasoline. The hydrocracker is particularly valuable in a refinery that is trying to maximize diesel production and reduce residual fuel oil. The hydrocracker yields a high volume of kerosene and light gasoil (distillate) of good quality (high cetane and low sulfur). However, its volume yield of naphtha is low and of low quality (low N+A). Markets that have very low sulfur limits for diesel also favor use of hydrocrackers, as the diesel product does not need subsequent hydro treating. The flexibility in the design and operation of hydrocrackers allows a wide range of feeds and of product yields. However this comes at very high capital and operating costs. A resid hydrocracker is a variant on the typical VGO hydrocracker. It is a similar unit yielding a similar range and quality of products, but it is designed to handle heavier vacuum resid as a feed.

Hydrocracking unit, or hydrocracker, takes gas oil, which is heavier and has a higher boiling range than distillate fuel oil, and cracks the heavy molecules into distillate and gasoline in the presence of hydrogen and a catalyst. The hydrocracker upgrades low-quality heavy gas oils from the atmospheric or vacuum distillation tower, the fluid catalytic cracker, and the coking units into high-quality, clean-burning jet fuel, diesel, and gasoline.

Hydrocrackers can take a wide variety of feeds depending upon the desired products. The most common are: VGO – This lighter fraction from the vacuum distillation unit is the most common feed for most hydrocrackers. It is a desirable feed when the refiner is attempting to maximize overall diesel production Coker gasoil – This VGO-range product from the coker is well suited to a hydrocracker, which is better able to handle its unsaturated components than an FCC unit is

Cycle oils and cracked distillates – These low-quality diesel-range streams can be hydrocracked to make jet fuel and gasoline-range material Atmospheric gasoil – This straight run diesel-range material can be hydrocracked to increase gasoline production by generating additional naphtha feed for the reformer.

Product’s A hydrocracker can produce a wide range of products depending upon what feed it processes and how it is designed and operated. Typical products are: Hydrocracked distillate – This is a high-quality diesel blendstock (high cetane and low sulfur) Hydrocracked gasoil (also known as unconverted oil) – It is a lowsulfur, VGO-range material that can be used as feedstock for FCC units or steam crackers Hydrocracked kerosene – This is a high-quality jet fuel (or diesel) blendstock with low sulfur and high smoke point Heavy hydrocrackate – This is a good-quality reformer feed, with moderate N+A and low sulfur Light hydrocrackate- This is a low-quality gasoline blend stock with low octane but also low sulfur Isobutane – This is valuable in a refinery with an alkylation unit that requires isobutane as a feedstock

Why AVUs Known As Mother Unit Of Any Refinery?

It goes without saying that different products require different treatment of their cuts/fractions. So, each of the secondary unit depends on CDU or AVU for their feed(raw material). Isn’t it analogous the traditional role played by the mother in a family? Hence, CDU/AVU is also called as the mother of the refinery. “Crude processing has commenced in the mother unit, i.e. atmospheric & vacuum unit (AVU) and products like LPG, naphtha, kerosene, gas oil, RCO, etc. are coming out of AVU,” said IOC in a BSE filing. Some of these products will require further processing in secondary units, which are also gearing up for commissioning. The whole complex is likely to take about 6-8 months for becoming fully operational in an integrated manner. This duration is normal for a refinery of this size and complexity. The overall purpose of a petroleum refinery is to process the lower valued (relatively) crude into valuable petroleum products wiz, LPG, gasoline, diesel, coke and petchem products and many others. Although refinery is complex integrated network of various process unit working in cohesion with each other to meet the above mentioned objective.

Assignment – 3 Kindly explain in details, what are critical operation controls of HGU, DCU, ISOM, DHDS & DHDT. What are the monitoring system of HGU & DHDT catalyst Performance ? Ans:HGU The primary objective of the Hydrogen Unit is to produce hydrogen to meet the quality of fuel produced from refinery and increase the yield from heavy oils. Hydrogen is used process crude oil into refined fuels, such as gasoline and diesel, and for removing contaminants, such as sulphur, from these fuels. Approximately 75% of hydrogen currently consumed worldwide by oil refineries is supplied by large hydrogen plants that generate hydrogen from natural gas or other hydrocarbon fuels, with the balance being recovered from hydrogen-containing streams generated in the refinery process Process Parameters: Control inlet temperature to about 380°C via steam to naphtha feed Preheater. Higher temperature: Higher activity of KATALCO 61-17 Higher absorption capacity of ZnO absorbent Too high temperature gives risk of polymerization. Low temperature: Risk of “5” slip leading to loss of activity of downstream catalyst. Monitor pressure drop: Increasing pressure drop=> coking. Recycle hydrogen ratio: Control hydrogen recycle to keep 0.2 Nm3 H2/kg naphtha feed.

Control hydrogen recycle to keep 0.03 Nm³ H2/Nm3 natural gas feed. Content of H2S and total 5 to be analyzed weekly to check for complete hydrogenation

DCU Coke yield in DCU are variables of following parameters: •

Feed CCR- higher CCR increases coke yield – but better from point of view of value addition- thus should not be targeted

• •

Recycle ratio (RR)- higher recycle ratio increases coke yield should be Targeted Reactor pressure- higher pressure increases coke yield- should be targeted But will be restricted to WGC suction pressure & system pressure drop

•

COT- Higher COT reduces coke make but increases gas make, reduces run length and coke cutting takes more time (hard coke)- to be optimised Space velocity higher the

•

space velocity lower the coke make- to be targeted in a limited way as it may result into coke carry over from reactor to MF column.

To recover valuable LPG from the DCU MF column over head reflux drum over head gas & naphtha. Treatment of DCU naphtha, LPG & off gas wrt S (H2S & RSH). Maintaining specifications of all the products.

ISOM With presence of dedicated Bz reactor, sulfur poisoning will affect first this reactor. Actions should be taken to prevent Isom catalyst contamination. • Without Bz reactor, sulfur will affect top bed of LEAD Isom reactor. • With H2S, partial activity could be recovered when no more H2S is entering. • At Isom operating conditions, organic sulfur are not converted to HC + H2S. • Hot hydrogen stripping with chloride injection is mandatory to recover good activity. • Left too long or in too high concentration sulfur poisoning could be permanent

DHDS & DHDT • • • • •

Sulfur compounds naturally occur in crude oil Sulfur in diesel enhances the pollution & contributes Significantly to particulate matters in exhaust emissions Sulfates are formed in the exhaust streams It leads to corrosion and wear of engine systems Factors Affecting DHDT Operation ■ Catalysts ■ Reactor volume ■ Reactor internals ▪ Reaction kinetics and thermodynamics ■ H₂ partial pressure effect ■ H₂S partial pressure effect ■ Reaction temperature & constraints ■ H₂ consumption ■ HYDROTREATING

• •

Nitrogen and sulfur removal Non-noble metal on alumina base .Ni-Mo for higher severity . Co-Mo for lower severity

What Are The Monitoring System Of HGU & DHDT Catalyst Performance ?

HGU Catalyst Syngas exit tubular reformer contains H2, CO, CO2, CH4 and water in chemical equilibrium at high temperatures. By means of the CO shift conversion an important portion of the CO content in the cracked gas is used for additional hydrogen generation. This process is exothermic and is limited by the chemical equilibrium The performance of the catalyst can be followed by means of the CO content in the outlet gas from shift reactors. Also the temperature profile through the catalyst bed and the temperature rise across the reactor is an indication of the catalyst performance.

PRE-DESULPHURIZATION Recommended For Bulk ‘S’ and ‘N’ Removal From naphtha (<2PPMw) which are poison to reforming and shift catalysts Typical Pretreatment Catalysts: Co-Mo/ Ni-Mo Oxides On Alumina Base Catalyst (Hydrogenation Catalyst) H2S formed from hydro treating reactions is removed by stripping operation

PDS Catalyst: TK-709 TK-709 is a high-surface area, low-activity catalyst with high hydrodemetallization (HDM) activity and metal storage capacity. It is typically used in various grading applications for all types of feeds, particularly where iron is encountered. It is especially suitable for olefin containing feeds, where activity grading is needed to prevent formation of gum. TK-711 TK-711 is a catalyst with high hydrodemetallization (HDM) activity, metal storage capacity and moderate hydrodesulphurization (HDS) activity. TK-437: TK-437, is a very high surface area catalyst for silicon pick-up and desulfurization of Coker naphtha feedstock. This catalyst has a low hydrodesulphurization (HDS) activity and used in combination with a guard catalyst. TK-431 TK-431, is a high surface area catalyst for desulfurization of Coker naphtha's. The metal loading of this catalyst gives a high hydrodesulphurization (HDS) and a high hydrodenitrogenation (HDN) activity. The pure alumina carrier used for ensures that this catalyst has a very high density and a higher surface area.

DHDT Catalyst Hydrotreating catalysts are primarily used to remove sulfur, nitrogen and other contaminants from refinery feedstocks. In addition, they improve product properties by adding hydrogen and in some cases improve the performance of downstream catalysts and processes.

Weighted Average Bed Temp. (WABT) ■ Attribute a weight fraction of the Catalyst bed to each TI A=25% catalyst B=35% catalyst C=40% catalyst eight WABT = 0.25*T1+0.35*T2+0.4*T3

Conversion Defined as % of feed that is converted to products in the hydrocracking unit ■ Conversion =(Feed -UCO) *100% / Feed ■ Conversion to XXX °C-final boiling point of heaviest product For Diesel, it is calculated upto 360°C Effects catalyst stability and product properties ■ Reactor Temperature=~ Conversion

H₂ to Oil Ratio ■ affects bed At ■ Improves distribution of materials ■ Reduces over-cracking ■ Suppresses coke formation